Method and mold for producing guiding, floating, and cementing shoes



July 16, 1929. c, K R 1,720,878

METHOD AND MOLD FOR PRODUCING GUIDING, FLOATING, AND CEHENTING SHOES Filed Nov. 23, 1927 IN V EN TOR.

A TTORNEYS.

Patented July 16, 1929.

UNITED STATES A I 1,720,878 PATENT OFFICE.

REUBEN C. BAKER, OF COALINGA, CALIFORNIA, ASSIGNOR TO BAKER CASING SHOE COMPANY, A CORPORATION OF CALIFORNIA.

METHOD AND MOLD FOR PRODUCING GUIDING, FLOATING, AND CEMENTING SHOES. I

Application filed November This invention relates to well drilling equipment and particularly pertains to a new method and mold for producing floating and cementing shoes such as described and claimed in my copending application entitled Guiding, floating and cementing shoe, filed November 23, 1927, Ser. No. 235,204.

In this copending application referred to I have disclosed a floating and cementing shoe composed mainly of non-metallic material, which is capable of use in guiding and floating a string of casing into a well and then as a cementing device to permit cement to be ejected into the well, but preventing the return of the cement from the well into the casing.

It is the principal object of the present invention to provide an improved method and mold for producing devices of the character referred to.

In carrying out the invention into practice, I provide a preformed casing shoe or similar element and a mold structure adapted to cooperate with this shoe. This mold structure is formed with a cavity within which the end of the casing shoe is inserted. Centrally of the mold, I provide means supporting a hollow core adapted to receive other preformed elements that are to be incorporated into the device and dispose them in proper relative positions within the casing shoe. The space surrounding the core in the lower end of the casing shoe and in the mold is then filled with cementitious material in liquid or plastic form. After this cement has set the mold and core is removed and the device is ready for use.

One form which the invention may assume is exemplified in the following description and illustrated by way of example in the accompanying drawings, in which:

Fig. 1 is a central vertical section through a mold structure contemplated by me and disclosing a casing shoe arranged in proper position so that the casting operation may be commenced.

Fig. 2 is a perspective view of the core structure shown in Fig. 1.

Fig. 3 is a central vertical section through the mold structure and the device being produced.

Referring more particularly to the accompanying drawings, 10 indicates what is commonly known as a casing shoe, which in fact is a tubular element ordinarily formed of 23, 1927. Serial No. 235,205.

steel and which is provided with an interiorly threaded portionll by means of which It 15 connected to the lower end of astring of casing. Just below this threaded portion, the nterior surface of the shoe is formed with a plurality of locking grooves 12.

The plug after being, formed is shown in Fig. 3 and comprises the casing shoe and a concrete plug 14 cast into the lower end thereof. The lower end of the plug is spheroidal and is of a diameter agreeing with the exterior diameter of the shoe. This plug is formed with a central valve chamber 15 wherein a spherical valve 16 is disposed. The upper end of the chamber is defined by a fiat valve plate 17 having a central opening 18 formed therein. This opening is surrounded by a valve seat 19. The area of the disk or plate 17 is greater than that of the valve chamber 15, so that the marginal edges of the plate 17 will be embedded within the sur rounding portion of the plug. A passageway 19 extends inwardly from the upper end of the plug andregisters with the valve opening 18 in the late 17 so that cement or other fluid may e pumped downwardly through the casing through the passageway 19 into the valve chamber 15. The lower end of the plug is formed with ports 20 which extend through the end of the plug from the valve chamber 15. A plate 21 of non-metallic friable material is arranged parallel to the valve plate 17 at the. bottom of the chamber 15 and is formed with openings communicating with the ports 20. This plate is also larger in diameter than the valve chamber 15 so that its marginal edges will also be embrladded in the surrounding portions in the As described in my copending application, the valve 16 is capable of cooperating with the valve seat to shut-off the passage of fluid through the plug and is also capable of assuming, under certain conditions, an unseated position permitting the free passage of fluid through the plug. The utility of this plug and its advantages over prior structures is set forth in the copending application mentioned.

This application is particularly concerned with the method and mold structure of producing the plug. The mold structure comprises a mold member'22 having a semispherical socket 23 formed therein. The diameter of this socket is such that it snugly receives the lower end of the casing shoe 10.

That is, the lower end of the casing shoe may be inserted a short distance into the end of the mold socket as shown in the drawings.

Projecting from the concave surface of the socket 23 in the mold is a plurality of cylindrical lugs 24: which project vertically. These lugs are arranged spaced distances apart about the center of the socket 23, so that when the casing shoe is arranged vertically on the mold the cylindrical lugs 24 will be arranged about its central axis.

To form the valve chamber 15, the passageway 19 and the ports 20, I provide a hollow core structure 25. .This core structure is formed of cardboard and includes a central section 26. Projecting coaxially from this central section upwardly is a tubular section 27 which joins the central section as illustrated. Extending downwardly from the bottom of the central section 26 are four tubes 28. These tubes are relatively spaced the same as the lugs 24:. The lugs 24 are of a diameter substantially agreeing with the interior diameter of the tubes 28 so that the latter may be arranged on these lugs 'to support the entire core structure.

During the forming of the core, the ball valve 16 is arranged within the central section of the core and the plates 17 and 21 are arranged on the core. It is seen that the central opening in the plate 17 is of the same diameter as the exterior diameter of the tube 27 so that the plate maybe slipped over this tube and arranged at the top of the central section of the core. Likewise, the openings in the plate 21 agree in diameter with the exterior diameter of the tubes 28 so that the latter may be arranged over the tubes 28 and disposed in place at the bottom of the central section of the core. In these positions the plates 17 and 21 will be correctly relatively positioned with respect to the casing shoe.

After the core has been formed, it is given a coating of paraffin and the tubes 28 are arranged on the lugs 24 so as to centrally support thecore structure relative to the casing shoe. The core may then be filled with sand so that it will not collapse. After this has been done a paper cap may be inserted in the top of the tubular section 27 and the space in the casing shoe and in the mold surrounding the core structure is filled with cementitious material, either in a liquid or plastic form, the level of the cement being on the same plane as the upper end of the tubular section 27. The cement is then permitted to harden and after it has hardened the mold is removed from the end of the casing shoe and the sand and core form is washed from the passageway 19 the valve chamber 15 and the ports 20.

It will also be noticed that after the material has hardened, the plates 17 and 21 of the core the spherical ball valve 16 is arranged within the central section 26 of the core.

After the core has been arranged properly relativeto'the mold 22, it is fillpd with sand or other suitable substance to prevent it from collapsing under pressure. A preformed casing shoe is then provided and arranged coaxially of the core with its lower end-inserted within the socket 23 of the mold 22.

It is seen that the lower end of the casing shoe will project a short distance within the socket 23. Cement is then filled in the spaces surrounding the core and within the lower end of the casing shoe and the socket 23 of the mold.

After the cementitious material has set, the casing shoe is removed from the mold and the plug will be firmly secured in the shoe because the cement Will enter the anchoring grooves formed on the interior sur face of the shoe. The paper or destructible portions of the core and the sand therein may then be washed out of the plug, leaving the shoe ready for use after proper hardenmg.

While I have disclosed the preferred form of my invention, it is to be understood that various changes may be made in its construction by those skilled in the art without departing from the spirit of the invention, as defined in the appended claims.

Having thus described my invention, what l claim and desire to secure by Letters Patent 1s:

1; A method of producing a device of the character described which comprises providing a preformed casing shoe, closing the lower end thereof with the removable mold, ar-

ranging a core structure within the shoe, placing a valve within the core structure, and supporting elements cooperating with the valve on the core structure, then filling the space between the shoe and the core structure with cementitious material, and removing the core and mold after said material has set.

2. A mold structure for forming a plug in a casing shoe which comprises a mold adapted to receive the end of a casing shoe, a core structure adapted to be supported within the shoe by the mold to form a valve chamber, and passageways from said valve chamber through the ends of the plug, said core being adapted to support a preformed valve,

and a pair of flat members forming the ends of the valve chamber in proper position relative to the casing shoe.

3. A mold structure for forming a plug in a casing shoe which compriseska mold adapted to receive the end of a casing shoe to enclose the same, said mold having lugs projecting u wardly therefrom, a core structure adapted to be supported within the shoe by the mold, said core structure comprising a central portion to form the valve chamber, a tubular portion extending upwardly from the center thereof, a plurality of tubular portions extending downwardly from the lower end of the central portion and adapted to engage the lugs on the mold to support the core structure in the shoe.

4. A mild structure for forming a plug in a casing shoe which comprises a mold adapted to receive the end of a casing shoe to enclose the same, said mold having lugs projecting upwardly therefrom, a core structure adapted to be supported within the shoe by the mold, said core structure comprising a central portion to form the valve chamber, a tubular portion extending upwardly from the center thereof, a plurality of tubular portions extending downwardly from the lower end of the central portion and adapted to engage the lugs on the mold to support the core structure in the shoe, said central portion being adapted to contain a preformed valve member, and to support preformed flat members atits ends that the same will be properly incorporated within the lug.

REU C. BAKER. 

